Here I will explain how to solve
the problem of “There
was a problem acquiring a personal certificate required to sign in, If the
problem continues, please contact your support team.” while login in to Lync communicator in windows 8.
Actually this problem occurs when our cached credentials of Lync get corrupted.
To fix this problem we need to delete existing certificates and login with your
details it will fix your “Cannot sign into Lync. There was a problem acquiring a certificate
from the server.”